Printing web materials

ABSTRACT

The present invention relates to machines for producing pattern effects on web materials of the type which includes one or more rows of dye dispensing nozzles mounted on a reciprocable carriage and arranged to apply a stream of colour to a material web as the web passes beneath the nozzles. Machines of this general type are known as &#39;&#39;&#39;&#39;polychromatic dyeing machines&#39;&#39;&#39;&#39;. In a polychromatic dyeing machine constructed in accordance with the present invention, the nozzle bearing carriage is arranged to be displayed by an electrically controlled means in dependence upon the amplitude of a predetermined master waveform.

Stankard et a1.

PRINTING WEB MATERIALS Inventors: Donald Rider Stankard, Coppicej ThomasWilliam Wilson, Bramhall, both of England English Calico Limited,Manchester, England Filed: Oct. 25, 1972 Appl. No.: 300,838

Assignee:

. U.S. Cl. 8/149, 8/151, 68/205 R Int. Cl B05b 13/04 Field of Search8/149, 151; 68/205 R Harris et al. 68/205 R Primary Examiner-William 1.Price Attorney, Agent, or FirmCushman, Darby &

Cushman [57] ABSTRACT The present invention relates to machines forproducing pattern effects onweb materials of the type which includes oneor more rows of dye dispensing nozzles mounted on a reciprocablecarriage and arranged to apply a stream of colour to a material web asthe web passes beneath the nozzles. Machines of this general type areknown as polychromatic dyeing machines. In a polychromatic dyeingmachine constructed in accordance with the present invention, the nozzlebearing carriage is arranged to be displayed by an electricallycontrolled means in dependence upon the amplitude of a predeterminedmaster waveform.

14 Claims, 3 Drawing Figures Apr. '2', 1974! PATENTEU APR 2 I974SBEEIZBFZ PRINTING WEB MATERIALS The present invention relates to theproduction of pattern effects on web materials, such as paper, woven orknitted textile fabric, or resin bonded fibre fabric, for example.

Machines are known for this purpose which comprise one or more rows offine nozzles to which a dye or dyes are fed. Each nozzle is arranged toapply a stream of colour to the web as the web passes beneath thenozzles. Each row of nozzles is mounted on a respective carriage whichis reciprocable transversely of the web by means of a direct mechanicalcoupling from a geared motor connected to a crank. Machines of thisgeneral type have been given the name polychromatic dyeing machines.

Many variations in patterns may be produced by polychromatic dyeingmachines of the above described known type, for example by varying thecolours fed to the nozzles; by varying the speed of the web through thepaths of the jets produced by the nozzles; by varying the frequency withwhich the carriage on which the nozzles are mounted are reciprocated; orby reciprocating two or more carriages'in, or out of, phase. However,all the patterns which can be produced by such variations are basedeither on continuous or discontinuous straight or substantiallysinusoidal lines.

It is an object of the present invention to provide a polychromaticdyeing machine in which'a greater variety of pattern types can beobtained than in the known machines employing crank drives for thenozzle bearing carriages.

According to one aspect of the present invention, a polychromatic dyeingmachine comprises a longitudinally displaceable-carriage bearing apluralityof nozzlesfor dispensing dye, and an electrically controlledmeans for displacing the carriage. in dependence upon.

the amplitude of a predetermined master waveform.

Preferably an electrical signal dependent upon the amplitude of thepredetermined master waveform is generated for controlling thedisplacement of the carriage.

In one embodiment of the invention, the master waveform is arranged toactuate a photoelectric cell to provide said signal for co'ntrollingthecarriage displacement. A A

In another embodiment, the master waveform is generated purelyelectronically.

According to a second aspect of the invention a method of dyeing webmaterials comprises supplying dye to a plurality of nozzles mounted on acarriage, progressively passing a web of material to be dyed through thejets paths of said nozzles and longitudinally displacing the carriage byan electrically controlled means in dependence upon the amplitude of apredetermined master waveform.

The invention will be described further, by way of example, withreference to the accompanying drawings, in which:- I

FIG. 1 is a diagrammatic view of a polychromatic dyeing machineembodying the present invention, only those parts of the machineessential to an understand ing of the invention having been illustrated;

FIG. 2 is a diagrammatic sectional view of one embodiment of a scanningunit forming part of the dyeing machine of FIG. 1 embodying the presentinvention; and

FIG. 3 is a diagrammatic illustration of how the embodiment of FIG. 1can be modified to include a pair of separately actuated nozzle bearingcarriages.

The polychromatic dyeing machine illustrated diagrammatically in FIG. 1includes a carriage 10 carrying a plurality of nozzles 12 arranged abovethe path of a material web 14 to be dyed, the web 14 being passed overrollers (not shown) in a direction substantially normal to the plane ofthe drawing.

In a known manner, means (not shown) are provided for pumping dye fromcontainers at ground level to constant head reservoirs (not shown)located above the nozzles 12 from where the dye can be selectably fed todesired nozzles 12 viaelectrically operable valves (not shown).

The carriage 10 is connected to one end of a longitudinally displaceablerack 16 adapted to be driven by 'a low inertia motor 18 via a pinion 20.The motor 18 must be capable of reversing'its direction of rotation andachieving full speed in the opposite direction in a very short period,an example of such a motor being a printed circuit, d.c. type.

The rack 16 is also connected to an assembly 22 comprising a flat plate24 having a surface 26 coated or formed such as to be substantially nonreflective to visible light. Formed on the non reflective surface 26 isa wedge-shapedportion 28 of diffusely reflective materialpAlternatively,the majority of the surface of the plate 24 canbe reflective with anon-reflective wedge shaped portion thereon. Located above the plate 24is a scanning unit 30 which will be described in detail below and whoseoutput is connected to one, input 32b of a differential amplifier 32. I

The machine also includes a circular turntable 34 which is rotatableabout a central axis 36 by means of a variable speed motor (not shown).One surface of the turntable has a non reflective portion 38a (shaded inFIG. 1) and a diffusely reflective portion 40. Located inwardly of thereflective portion 40 is a further non reflective portion 38b ofcircular outline. The shape of the outer periphery of the reflectiveportion is chosen to define a master waveform controlling the movementof the nozzlebearing carriage 10, as will become apparent below..

Located over the, turntable is a second scanning unit 42 identical inconstruction to the unit 30, the output of the second scanning unit 42being connected to asecond-input 32a of the differential amplifier 32.The output of the differential amplifier provides an error signal whichcontrols the low inertia motor 18 via a three-term controller 44, aswill be described further below.

FIG. 2 illustrates in more detail the construction of the scanning unit42. The unit 42 comprises a light bulb or lamp filament 46 located atone end of a chamber 48 and arranged to direct a line of light 50,extending perpendicular to the drawing as viewed in FIG. 2, onto thesurface of the turntable 34 so that this line of light 50 liessubstantially radially relative to the turntable axis 36 and crosses thereflective portion 40. The unit 12 also includes a photocell 52 locatedat one end of a further chamber 54 and arranged to receive reflectedrays from the reflective portion 40. A light-proof enclosure 56 ensuresthat the photocell 52 receives substantially no light except that whichis reflected thereto from the filament 46 by the reflective portion 40.The filament 46 is supplied with electrical power via a pair ofterminals 58 and the output of the photocell 52 is connected to afurther pair of terminals 60.

The scanning unit 30 is identical to the unit 42 except that it directsits line of light 62 onto the plate 24 so that it extends in a directionperpendicular to the longitudinal movement thereof.

It will be appreciated that the amount of light received by thephotocell 52 in the scanning unit 30 depends upon the position of thereflective wedge portion 28 relative thereto and hence upon the positionof the rack 16 and the nozzle bearing carriage 10. The output of thephotocell at the terminals 60, and hence at the input 32b of thedifferential amplifier, is therefore indicative of the instantaneousposition of the nozzle bearing carriage l0. 1 1

In a corresponding manner, the amount of light received by the photocell52 in the scanning unit 42, and hence the magnitude of the output signalat the terminals 60, is dependent upon the radial dimension of thereflective portion .40 at any given instant, this output signal beingapplied to the second input 32a of the differential amplifier 44. Thelatter amplifier 44 provides an error signal dependent upon thedifference between the signals from the photocells in the scanning units30, 42, the controller 44-being arranged to drive the motor 18 todisplace the rack 16 in a direction to reduce the error to zero. Thusthe position of the rack, and hence the position of the nozzle bearingcarriage 10, is made to be dependent upon the amplitude of the masterwaveform 40a, defined by the outer periphery of the reflective portion40, at the location of the line of light 50. As the turntable rotates,carrying with it the master waveform 40a, the carriage is thus caused tobe dis placed in dependence upon the instantaneous amplitude of themaster waveform.

In order to change the movement effected by the car riage it ismerelynecessary to substitute a new master waveform. This can be done inmany ways, for example, by providing the reflective and non reflectivesurfaces on a disc which is carried by the turntable and which isreplaced to change the master waveform, or by arranging for thereflective and non reflective surfaces to be carried directly by theturntable, the turntable itself then being changed to provide the newmaster waveform. It-may be desirable for a given dyeing machine to havemore than one nozzle bearing carriage 10 in form dependent signals fromthe appropriate scanning unit. The two turntables 70, 72 are carried ona common base 74 and are driven by a common variable speed motor 76controlled by a conventional electronic controller 77, the spindle ofthe turntable 70 being connected to the spindle of the turntable 72 bymeans of pulleys 78, 80 and a belt 82. By varying the pulley ratio,

the turntables 70, 72 may be driven at the same'or at different speeds.

' The abovedescribed embodiments employ electrical feedback control tomake the carriage 10 follow the master waveform. However, it is alsopossible to employ mechanical feedback to achieve/same, although theformer is preferred. One way of achieving mechanical feedback is tomount the scanning unit associated with the turntable sothat it isdisplaceable relative to the turntable in response to movement of thenozzle bearing carriage, for example by providing a direct mechanicallinkage therebetween. The line of light from the scanning unit isdirected onto the periphery of the reflective portion carried by theturntable, the electrical output of the scanning unit being dependentupon the proportion of the line of light which lies on the reflectiveportion of the turntable. An electronic controller is provided which isarranged to energisethe motor driving the rack such as to displace thescanning unit to equalise the proportions of reflectiveand nonreflectivematerial falling under the line of light from the scanning unit. Thenozzle bearing-carriage attached to the rack thus again follows themaster waveform defined by the shape of the boundary between thereflective and non-reflective portions. I

Although the above describedarrangement using a low inertia d.c. motorto drive the rack is preferred, an alternative arrangement is to drivethe rack by means of a pair of electric motors which can drive the rackin opposite directions via a pair of particle couplings, the couplingsbeing selectabiy electrically actuated to transmit the drive from thatmotor which will move the rack to follow the master waveform.

In a further modification, the master waveform scanned bythe scanningunit is in the form of a tape or belt, either opened ended or closedloop, which bears reflective and non-reflective coatings, the boundarybetween which defines the shape of the master waveform.

Alternatively, the master waveform-may be defined purely electronicallyby means of a conventional electronic waveform generator. In thisembodiment the waveform generator provides the signal applied to theinput 32a of the differential amplifier which is compared with a signalat 32b from a scanning unit'30 monitoring the position of a wedgeassembly 22 to provide an error signal for controlling the motor, as inthe FIG. 1 embodiment. i

We claim:- I

1. A polychromatic dyeing machine comprising a longitudinallydisplaceable carriage, a plurality of nozzles for dispensing dye mountedon said carriage, and an electrically controlled means for displacingthe carriage in dependence upon the amplitude of a predetermined masterwaveform.

2. A machine according to claim 1 further comprising means forgenerating an electrical signal dependent upon the amplitude of thepredetermined master waveform, said electrical signal being utilised forcontrolling the displacement of the carriage.

3. A machine according to claim 2 further comprising a photoelectriccell means which is arranged to be actuated by the master waveformto'provide said electrical signal for controlling the carriagedisplacement.

4. A machine according to claim 3 further comprising a movable firstcarrier means, and an elongate portion of reflective material providedon a non-reflective background onsaid carrier, the amplitude of whichreflective portion defines said master waveform, the arrangement beingsuch that said electrical signal for controlling the carriagedisplacement which is obtained at the output of said photoelectric cellmeans is dependent upon the instantaneous amplitude of said reflectiveportion at a predetermined stationary reference position past which saidreflective portion is movable on said first carrier means.

5. A machine according to claim 4 in which means are provided forprojecting a narrow, elongate, light band onto said first carrier meansat said reference position such that said light band extends in adirection substantially perpendicular to the instantaneous direction ofmovement of a point on said first carrier means moving through saidreference position.

6. A machine according to claim 5 further comprising means for producinga second signal whose magnitude is dependent upon the position of thecarriage, and a comparator means for comparing the first signal from thephotocell with said second signal, the comparator providing an errorsignal corresponding to the difference between said first andsecondsignals, and a control means which controls the movement of thecarriage such as to reduce the error to zero.

7. A machine according to claim 6 further comprising a rack and pinionadapted to displace said nozzle bearing carriage in response to themagnitude of the error signal from said comparator means.

8. A machine according to claim 7 further comprising a low-inertia d.c.motor for driving said pinion in a direction to move said carriage suchas to reduce said error to zero.

9. A machine according to claim 6 further comprising secondphotoelectric cell means for deriving said second signal dependent onthe carriage position, sec ond carrier means connected to said carriageand carrying a wedge-shaped portion of reflective material on anon-reflective background, and means for projecting a narrow, elongate,light band onto said second carrier means at a second reference positionsuch that the latter light band lies across said wedge-shaped portion ofreflective material and extends in a direction perpendicular to thedirection of movement of said second carrier means resulting fromlongitudinal movement of said carriage.

10. A machine according to claim 1 in which there are a plurality ofsaid longitudinally displaceable, nozzle bearing carriages each of whichis adapted to be controlled by a respective master waveform.

11. A machine according to claim 10 further comprising a plurality ofmovable carrier means each of which carries a respective one of saidmaster waveforms and a common mechanical transmission system for saidplurality of carrier means whose transmission ratios are selectablyadjustable to vary the relative operating speeds of said carrier means.

12. A machine according to claim 1 further comprising a movable carriermeans, means defining elongate, side by side, reflective and nonreflective surfaces carried by said carrier means, the boundary betweensaid reflective and non-reflective surfaces defining said masterwaveform, a scanning device which is mechanically connected to thecarriage, means in the scanning device for projecting a narrow,elongate, light band onto said carrier means at a stationary, referenceposition such that the light band traverses the boundary between saidreflective and non-reflective surfaces and extends in a directionperpendicular to the instantaneous direction of movement of a point onsaid'carrier means moving through said reference position, photoelectricmeans in said scanning device adapted to provide an output signaldependent upon the proportion of said light band which falls uponreflective material at said reference position, and control means fordisplacing said carriage such as to equalise the proportions of saidlight band falling on reflective and non-reflective materialrespectively.

13. A machine according to claim 1 further comprising means forgenerating said master waveform purely electronically.

14. A method of dyeing web materials comprising supplying dye to aplurality of nozzles mounted on a carriage, progressively passing a webof material to be dyed through the jet paths of said nozzles andlongitudinally displacing said carriage by an electrically controlledmeans in dependence upon the amplitude of a predetermined masterwaveform.

2. A machine according to claim 1 further comprising means forgenerating an electrical signal dependent upon the amplitude of thepredetermined master waveform, said electrical signal being utilised forcontrolling the displacement of the carriage.
 3. A machine according toclaim 2 further comprising a photoelectric cell means which is arrangedto be actuated by the master waveform to provide said electrical signalfor controlling the carriage displacement.
 4. A machine according toclaim 3 further comprising a movable first carrier means, and anelongate portion of reflective material provided on a non-reflectivebackground on said carrier, the amplitude of which reflective portiondefines said master waveform, the arrangement being such that saidelectrical signal for controlling the carriage displacement which isobtained at the output of said photoelectric cell means is dependentupon the instantaneous amplitude of said reflective portion at apredetermined stationary reference position past which said reflectiveportion is movable on said first carrier means.
 5. A machine accordingto claim 4 in which means are provided for projecting a narrow,elongate, light band onto said first carrier means at said referenceposition such that said light band extends in a direction substantiallyperpendicular to the instantaneous direction of movement of a point onsaid first carrier means moving through said reference position.
 6. Amachine according to claim 5 further comprising means for producing asecond signal whose magnitude is dependent upon the position of thecarriage, and a comparator means for comparing the first signal from thephotocell with said second signal, the comparator providing an errorsignal corresponding to the difference between said first and secondsignals, and a control means which controls the movement of the carriagesuch as to reduce the error to zero.
 7. A machine according to claim 6further comprising a rack and pinion adapted to displace said nozzlebearing carriage in response to the magnitude of the error signal fromsaid comparator means.
 8. A machine according to claim 7 furthercomprising a low-inertia d.c. motor for driving said pinion in adirection to move said carriage such as to reduce said error to zero. 9.A machine according to claim 6 further comprising second photoelectriccell means For deriving said second signal dependent on the carriageposition, second carrier means connected to said carriage and carrying awedge-shaped portion of reflective material on a non-reflectivebackground, and means for projecting a narrow, elongate, light band ontosaid second carrier means at a second reference position such that thelatter light band lies across said wedge-shaped portion of reflectivematerial and extends in a direction perpendicular to the direction ofmovement of said second carrier means resulting from longitudinalmovement of said carriage.
 10. A machine according to claim 1 in whichthere are a plurality of said longitudinally displaceable, nozzlebearing carriages each of which is adapted to be controlled by arespective master waveform.
 11. A machine according to claim 10 furthercomprising a plurality of movable carrier means each of which carries arespective one of said master waveforms and a common mechanicaltransmission system for said plurality of carrier means whosetransmission ratios are selectably adjustable to vary the relativeoperating speeds of said carrier means.
 12. A machine according to claim1 further comprising a movable carrier means, means defining elongate,side by side, reflective and non reflective surfaces carried by saidcarrier means, the boundary between said reflective and non-reflectivesurfaces defining said master waveform, a scanning device which ismechanically connected to the carriage, means in the scanning device forprojecting a narrow, elongate, light band onto said carrier means at astationary, reference position such that the light band traverses theboundary between said reflective and non-reflective surfaces and extendsin a direction perpendicular to the instantaneous direction of movementof a point on said carrier means moving through said reference position,photoelectric means in said scanning device adapted to provide an outputsignal dependent upon the proportion of said light band which falls uponreflective material at said reference position, and control means fordisplacing said carriage such as to equalise the proportions of saidlight band falling on reflective and non-reflective materialrespectively.
 13. A machine according to claim 1 further comprisingmeans for generating said master waveform purely electronically.
 14. Amethod of dyeing web materials comprising supplying dye to a pluralityof nozzles mounted on a carriage, progressively passing a web ofmaterial to be dyed through the jet paths of said nozzles andlongitudinally displacing said carriage by an electrically controlledmeans in dependence upon the amplitude of a predetermined masterwaveform.